For many years the B2 Bomber was used as an enclosure tool, particularly as part of tenuki joseki. However, that approach has become less common in favor of other more favorable variations. No pro in modern analysis will willingly give his or her opponent a B2 Bomber. As such, the B2 Bomber shows up mainly in complex fighting and is an overwhelmingly powerful shape that can shift the entire tempo of the game.
Before proceeding, please note that the following discourse is aimed mainly at advanced Go players. Unless you've reached zero-dan (alias zeri-dan), don't try to understand fully the intricacies of the B2 Bomber. While you may attempt to reproduce it in your own play, be aware that the nuances may alter its implications, although it is hard not to win when you have it.
ekberg: The secret of the B2 Bomber is of course that it contains not less than two empty triangles, which radiates absolutely no influence, and thus the shape is virtually undetectable on the enemy's radar.
The following diagram illustrates the B2 Bomber's offensive capabilities.
Here, we see that Black's position has completely smothered White's stone. For all tactical purposes, White has been eliminated from play. The B2 Bomber here has succeeded in meeting its objectives. As such, many times the wary and wise opponent will realize the incoming threat, and act to stop the formation of a B2 Bomber.
Here the white stone is decimating Black's entire position. Notice the major difference between this and the earlier diagram. Before, the white stone was weak; here, it is preventing an ideal formation and restricts Black's influence to a limited sphere. The difference is both striking and remarkable.
For another thing, note that the B2 Bomber has 10 liberties (no, this is not a lie. Count yourself and you'll see the astonishing truth -- 10!). This number, the 10, which in Jewish mysticism is full of cosmic power, makes it very difficult to capture a B2. Indeed, as statistical analysis done by a Korean-Indian-Russian team over three years shows, 10 is an unparalleled number in capturing races; the average tends to be near 5 or 6.
The B2 Bomber certainly is a powerful shape, and it 'certainly' never fails to amaze.
An interesting metalogic structure emphasizes the strength of the B2 Bomber. A KGS regular, trestles, once mentioned the proverb ignore all proverbs?. Strangely enough, there are almost no proverbs about the B2 Bomber as opposed to -- say, the Carpenter's Square. This peculiarity may have something to do with the complex, stratego-tactico dimorphic structure of the B2 Bomber, or it may represent a wish by Pro players to repress Amateur knowledge. Either way, trestles' proverb applies to the B2 Bomber, underscoring its strength.
Clearly the creation of a B2 Bomber is game-deciding. If you can understand its strength, the folk-saying goes, then you are a 5d (though in practical play many 3ds attempt to use it, similarly to how many amateurs attempt to copy Pro-level fuseki). A great deal of higher strength play is a subtle cut and thrust attempt to design a B2 Bomber and launch it before the opponent does so him or herself.
This position is a common enclosure shape. Later in the game, perhaps over the course of whole-board fighting, it may evolve into the following diagram:
This position is learned to be a very dangerous one at about the 5k level -- a B2 Bomber is under formation. The wise player knows that only three moves more are needed to finish the B2 Bomber formation and so end White's ability to resist. White must strike now. The entire balance of the game is at risk; no mistakes can be made at this point.
Compare the next two diagrams:
Both take the corner enclosure and add a stone, whether it be white or black. The primary difference between the diagrams, besides for the obvious points, lies in a principle discovered by a Korean pro:
Yes! As strange as it may seem at first, the B2 Bomber, when formed, is an example of Differential Influence!
(Upon rereading this, I came to realize that SL does not have any adequate pages on Differential Influence. Hopefully, one will be made or I will be forced to explain this high-dan concept in this lowly page about the B2 Bomber!)
Onwards to another point:
This is a position from a recent pro game. The first thing that one may notice is that Black has moved an extra time. That is because White naturally panicked after seeing Black's formation in the center and decided to pass. White did recover his stamina and managed to continue play after downing a cup of water. (As a side note, please note that the pro did not drink alcohol. Though the situation is scary, alcohol is not needed to deal with B2 Bombers. A B2 Bomber is not a good reason to become a drunkard (unless it is flying above your head and you see the bombs falling).)
The second thing noticeable is that Black has a surplus of power in the center. Though Black has neglected the corners, the rest of the game will be a hard fight for White, as groups are chased to the waiting B2 Bomber that is hovering in the middle.
And indeed, 104 moves later, after a toughly fought ko, White did resign.
Modern thought on such play is that instead of passing, White should have dynamically attacked the B2 Bomber by playing in the center. This ties into Differential Influence:
There is a proverb, saying, A Bomber in play adds 4 to your kyus. This example shows the only possible way for White to reach Black's level of play.
Notice that Black still has the upper hand. The stone occupies tengen, which is the highest position on the board! This "small" difference in position is so critical that some have pushed for banning black from opening at tengen. Of course, such an idea is absurd. The B2 Bomber, despite appearances to the contrary, is stoppable.
The most basic idea for striking at a B2 Bomber is
Do not panic!
The B2 is frightening, no one can deny that. But if you let it get to you, you've already lost half the battle. A positive mindset will do wonders, especially in such a difficult position.
(Though it is true that you made a huge blunder in letting the B2 come into existence. You should certainly be irked at yourself for that -- but do not let it influence your playing.)
Understanding the second idea is easier if we look at the following diagram:
Notice that White has played precisely at the tip of Black's formation -- thusly diffusing all its influence in that direction. This is a key idea: for all its benefits, the B2 is not a useful territorial shape. Instead, it is influential -- and in any fight, you should seek to ruin its influence.
Black is not going to let White push him around. He knows how strong his shape is, and he's going to fight the position out. This is a very violent reply, and one that is judged optimal. Anything else is a compromise and can lead to disaster for black.
All of this, however, is discussing the attacking of a B2 when it is placed in tengen as a ferocious opening strategy. What if the B2 appears elsewhere in the game?
This is a very realistic depiction of how a B2 could come into play. Here, black faces a major dilemma, namely how to deal with the amazing threat.
I'll admit that my puny brains can not handle such a problem. As shown earlier, often B2 Bombers are part of complex 4p-strategy. I am not 4p, so I know not what to do :(.
A possible solution is to use ground to air missiles, or perhaps even air to air missiles to take the bomber out before it does any harm, as with the contra strategy. One problem with this solution is that your opponent may object to you carrying missiles.
Obviously, the answer to that is another missile.
This is what is left after one strategic missile is launched. The difference is plain to all -- the B2 Bomber is gone, and Black is free to expand into the lower-middle. If only all problems in life were so easily solved.
BenjaminGeiger: The inevitable result of air-to-air missiles:
(Lynx:) Fantastic! I never approached the B2 Bomber on that angle! On other pages you state that you a kyu. Please do not mock us with such lies. Once you spout such wisdom at us, any claim of being a kyu is immediately destroyed.
Bildstein: Indeed, with such stunning insight, Sebastian is clearly giving away that he is at least of 4p strength. This leads me to believe that Sebastian may indeed be Tartrate. Perhaps he deserves an entry in TartrateGossip?
Kyu players often have trouble make effective use of the B2 in play, because they often lack a deep enough understanding of the difference between light and thin, and heavy and thick. As a sort of stepping stone to the effective use of the B2, kyu players can try this, admittedly thinner, cousin of the B2.
It has some interesting qualities. For example, it is very difficult to stop the creation of the "thinner B2". Consider the above diagram after White has played the three marked stones with her first three moves. It is very difficult for Black to stop her, and if he tries, he ends up with his stones too close to White's thickness.
Lynx: Also note that Black would find it quite difficult to play inside the B2 Bomber and escape. 'Minor' facts like that are essential to fully appreciating a shape's strength.
However, I wonder if the B2Bomber is solely a high dan shape. I see it being employed quite often by low level kyus. Virtual beginners employ it quite often. Perhaps there is an intuitive power to this shape that makes it powerful for all levels of play.
Jewdan?: I feel that, at this point, it is fair to discuss a variant of the B2 Bomber I have discovered that is simpler for kyu-level players to employ and that may deserve professional-level investigation. I call it the Rift.
Note that it is one move short of forming a B2 Bomber, so it is more efficient to make, and for reasons to soon be discussed, more difficult to see coming. However, the missing stone is strategically chosen: note that the Rift has THREE empty triangles! The stealth of the B2 Bomber is based upon only two empty triangles, but the Rift's three has so little influence that, not only is it impossible to detect upon radar, but it actually sucks in influence of other groups on the board to fill in its void! Unless the opponent were actively looking for the source of the loss of power, he will never find the Rift. Nicknames for this formation are black hole (if the stones are white), white hole (if the stones are black), and the wormhole (if the stones are somewhere in between; with the Rift, sometimes the powerful vortex of the shape distorts the light reflecting off the stones to the extent that it becomes impossible to distinguish their color... in such cases, claim the group is yours even if you did not play it).
Now, there are defects in this shape that must be considered before taking such chances. This formation sucks in influence regardless of which color has it, so it is possible to damage oneself more than one's opponent. In addition, the opponent can reduce the damage inflicted by the shape and eliminate the potential for it to become a full-fledged B2 Bomber by playing the so-called nose tesuji (hitting the B2 Bomber where its nose should be). In most circumstances, however, the opponent will not even see the formation even after the game is over, and in the case of the nose tesuji, the Rift still has massive fighting power absorbed from the other groups with which to retaliate.
Because of the third empty triangle, one might complain that the Rift lacks the ten liberties that prove the shape to be complete. While it is true that the Rift lacks the overwhelming power of the B2 Bomber, note that it does have nine liberties. Nine is three threes, and three is the number for good. In Hebrew (the language used in Hebrew mysticism), using words with similar roots in the same sentence cause those words to be interpreted more strongly. Using a word twice means that it is at the most superlative form in the natural world, and three means that it is supernatural and incomprehensible to mere mortals. Well, the Rift has FOUR threes: three sets of three liberties, and three empty triangles! This means that this formation is so good that it might make the rumored god of Go nod with approval.
An astute reader will also notice that there is proof for the strength of the Rift found in a failed ladder.
The advantage of the Rift's undetectability disappears with all of its empty triangles filled in, but this only serves to enable weaker players to see the awesome fighting power of the shape. Even with nearly all of the Rift's liberties filled in, Black must tremble in apprehension of the destruction he is about to suffer. Perhaps it would be better if he could not see it.
In estimating the Rift's territorial value, we can use the proverb regarding failed ladders: "Every move in a failed ladder is worth seven points." Since the Rift is essentially a failed ladder, and since the Rift has five stones, then the Rift is worth thirty-five points. Clearly, this swing of the score will alter the outcome of any game.
As a weaker player, this is as far as I could comprehend this formation. The analysis of stronger players would be appreciated.
Anonymous: Go Seigen favors this shape and you can find it in game # 2 of AGA starter pack.
in the diagram is the solution. Black completes a second B2 Bomber and White resigns.
Ask any weak 10kyu and they will immediately say this shape is seki. However, a stronger player will recognize a B2 Bomber in the making.
Black is brilliant. Letting the opponent capture your B2 Bomber may seem like suicide, and in a way it is. Usually losing your B2 Bomber is a game-ending disaster, but this is a special case. This kamikaze play aims to exploit the properties of B2 Bomber in the corner. White is forced.
Black is like a phoenix rising from the ashes! So powerful is this play that white has no choice but to play on the point of symmetry. However, black calmly replies at and white's eyespace is reduced to bent four in the corner. White is dead.
With all that said it is easy to go astray. Black at would be a grave mistake. Even a dan player who is unfamiliar with the ways of the B2 Bomber might claim they are "miai". To you, dear reader, the fallacy behind that statement should be obvious.
Anonymous: And what happen if White play 2 at 3?
Superdave: This is all theoretical, because normally after White captures the B2, Empty will have so much influence that Black and White will simultaneously resign and Empty wins. But anyway, with your variation, if 2 at 3 then 3 at 2:
lackita?: I think this position needs to be reevaluated. Notice that forms the tip of a counter B2 Bomber, which could spell disaster if Black does not capitalize on the filled empty triangles.
Anonymous: White has 2 rifts in the beginning, which is probably why they got undetected and white captures a B2 Bomber and black has to resign.
cannot be below 1 because it would be self-atari, and white cannot tenuki because just look at how many white stones there are. Black will capture White's two stones, and then we get into dan-level ruleset variations.
In the Japanese variation, white recaptures. White loses one prisoner in this exchange, but with all those white stones at stake the investment of one stone is a Picnic Play for White--she obviously will take this chance. With perfect play, however, Black will win by infinity. Along the way, White will run out of stones and go around the room stealing other people's stones, demonstrating the observation that the B2 "sucks influence".
In the Superko variation, both players must play superko threats every couple moves. This gets complicated and will end up with a B2 Bomber Race? where both players must create B2 Bombers in order to create symmetric superko threats. Because this happens at a point in the middle game where there isn't much room to create Bombers, it will lead to an influence-sucking situation analogous to the Japanese version where both players will need to go around the room stealing gobans.
The B2 Bomber and AlphaGo-Zero
IngoA: Not really much is known, but rumors have it that within the AlphaGo-Zero project the program turned out to discover the formation and likes it very much. However, Go experts within the DeepMind company decided to keep the discovery secret and to use it later as a surprise weapon against LeelaZero, ELF, and other bot "newcomers".
Additional shapes that are similar:
The opposite in Karma relationships to the B2Bomber is the BloodyL
ChaoSpectre: I do not think that the BloodyL is the "opposite" of the B2Bomber. Although the Carpenter's Square is something formidable to deal with, the Box connection is quite useful, if carried out. The L has 11 liberties, which is more than comparable to the Bomber's 10. Also, note that the L is only one stone away from being a Bomber.
ProtoDeuteric: Chao, I think that you should realize that this is a humor page. Notice the "deathstar" comment below and the "Enterprise" comment above.
ChaoSpectre: What good is humour that doesn't make sense? ;)
Although... it does seem like the L is a Bomber that has taken AA fire and had a part shot off. This means the Bomber will crash at any point unless repaired, wasting a move to play an immensely thick and useless point, and giving white sente to roll out some SAMs or some more AA guns. Or you know, play somewhere else...
I think the deathstar formation should not be ignored
cliftut: Recently some research and experimentation has yielded a dramatic find; it seems that the power of the B2 Bomber can even overcome the bad shape of the EmptyTriangle! This diagram, although just an example, shows how dynamic the empty triangle becomes when used with the B2 Bomber. Such an empty triangle is known as an Escort.
This is a highly advanced technique which has rarely been witnessed even in high-ranking professional games. Even though these stones are not directly connected, they are considered as one group, known as a Squadron. A B2 in a Squadron is said to be "in formation", and has been jokingly referred to as an "Alpha Leader".
One of the most amazing things about this formation is how dynamic it truly is. Escorts may be strategically placed to enhance the B2's already stunning influence in any direction, or (and this is more often the case) to protect its few weaknesses. Where the B2 would in most cases be surrounded and suffocated, a single escort can give it the support it needs to break out of the enemy's hold. While the B2 Bomber by itself is very difficult to smother, it is nearly impossible to defeat when in formation.
It is believed that this is only a single way that the B2 Bomber can be enhanced, and that other shapes may be able to act as escorts or other forms of support. Information should be added here as it arises for the betterment of our understanding of the B2's dynamic nature.
Gillis: It is no wonder that Koreans, even as far back as 1996, started to adopt the B2 bomber. This is a very famous game from that time. Yang Jae-ho 9p as black and Seo Bongsoo 9p as white. This was the finals of the 4th Mobile Cup.
In this game, Seo Bongsoo 9p(w) had just wedged black. Black naturally blocks at . But then suddenly white throws-in at , a fatal overplay. Whites plan is to save the marked stone in sente because black must connect at the marked spot... Or that is what Seo Bongsoo 9p(w) expected.
Yang Jae-ho 9p(b) found this excellent punishment at and now we see just how big whites overplay was. Black is just one move away from creating the B2 bomber.
Rumors has it that Seo Bongsoo 9p(w) accidentally swallowed his piping hot tea down the wrong throat as he saw blacks response. However, what remains behind closed doors remains behind closed doors.
After some recovery from the shock as well as carefully cleaning up the somewhat lukewarm tea droppings from the go board, Seo Bongsoo 9p(w) decided to play an even more shocking yet understandable move at , helping black create ideal shape. As we can see, it is drilled so hard into a professionals fundamentals to not waste the move just played. It would be unacceptable and embarrassing for white to give in to his mistake at this point. Had Seo Bongsoo 9p(w) accepted his error and resigned in face of the B2 bomber, he would have to commit Seppuku which was introduced at a few Go schools at the time. And who wouldn't chose losing the game over losing your life?
White then sets out on a heroic mission to try overconcentrate blacks B2 bomber at . Seo Bongsoo 9p(w) probably still saw a glimpse of hope in this game, as blacks B2 Bomber was facing the bottom part of the board and thankfully not the center. However, whites left side wall and center stone influence had been completely nullified by the B2 bomber. In the end, Yang Jae-ho 9p(b) took home the easy victory.